package com.itheima.filter;

import com.alibaba.fastjson.JSON;
import com.itheima.common.BaseContext;
import com.itheima.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.AntPathMatcher;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@Slf4j
@WebFilter(filterName = "loginCheckFilter",urlPatterns = "/*")
public class LoginCheckFilter implements Filter {

    /**
     * 路径匹配器，支持通配符
     */
    public static final AntPathMatcher PATH_MATCHER = new AntPathMatcher();

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        HttpServletRequest httpServletRequest = (HttpServletRequest) request;
        HttpServletResponse httpServletResponse = (HttpServletResponse) response;

        Long id = (Long) httpServletRequest.getSession().getAttribute("employee");
        BaseContext.setCurrentId(id);

//        1、获取本次请求的URI
        String requestURI = httpServletRequest.getRequestURI();
        log.info("拦截请求：{}",requestURI);
//        2、判断本次请求是否需要处理
        String[] notFiltUrls = {
                "/employee/login",
                "/employee/logout",
                "/backend/**",
                "/front/**",
                "/user/sendMsg",
                "/user/login",
                "/doc.html",
                "/webjars/**",
                "/swagger-resources",
                "/v2/api-docs"
        };
        boolean check = check(notFiltUrls,requestURI);
//        3、如果不需要处理，则直接放行
        if (check) {
            log.info("本次请求{}不需要处理",requestURI);
            chain.doFilter(httpServletRequest,httpServletResponse);
            return;
        }
//        4-1、bs端判断登录状态，如果已登录，则直接放行
        if (httpServletRequest.getSession().getAttribute("employee") != null) {
            log.info("用户已登录，用户id为{}",httpServletRequest.getSession().getAttribute("employee"));
            chain.doFilter(httpServletRequest, httpServletResponse);
            return;
        }

//        4-2、移动端判断登录状态，如果已登录，则直接放行
        if (httpServletRequest.getSession().getAttribute("user") != null) {
            log.info("用户已登录，用户id为{}",httpServletRequest.getSession().getAttribute("user"));
            Long userId = (Long) httpServletRequest.getSession().getAttribute("user");
            BaseContext.setCurrentId(userId);
            chain.doFilter(httpServletRequest, httpServletResponse);
            return;
        }

        log.info("用户未登录");
//        5、如果未登录则返回未登录结果,通过输出流方式向客户端页面响应数据
        httpServletResponse.getWriter().write(JSON.toJSONString(R.error("NOTLOGIN")));
        return;

    }

    /**
     * 路径匹配，检查本次请求是否需要放行
     * @param notFiltUrls
     * @param requestURI
     * @return
     */
    public boolean check(String[] notFiltUrls, String requestURI) {
        for (String notFiltUrl : notFiltUrls) {
            if (PATH_MATCHER.match(notFiltUrl,requestURI)) {
                return true;
            }
        }
        return false;
    }
}
